Crystal Castles is an arcade game released by Atari, Inc. in 1983. The player controls a cartoon bear by the name of Bentley Bear, who has to collect gems located throughout trimetric-projected rendered castles while avoiding enemies out to get him as well as the gems.
Crystal Castles is notable for being one of the first arcade action games with an actual ending, whereas most games of the time either continued indefinitely, ended in what was termed a "kill screen" or simply just restarted from the first level, and to contain advance warp zones.
Crystal Castles has nine levels with four castles each, and a tenth level which features a single castle — the clearing of which ends the game. Each of the 37 trimetric-projected castles consists of a maze of hallways filled with gems and bonus objects, and also includes stairs, elevators and tunnels that the player can use as shortcuts. The three-letter initials of the player with the highest score are used to form the first level's castle structure. When all gems in a castle have been collected, the player moves on to the next castle. The player can also skip some castles and acquire additional lives and points by using secret warps activated by making Bentley Bear jump at special locations.
A trackball and "jump" button are used for controlling Bentley Bear's motions. Gems are collected by simply walking over them, and a bonus is given upon collection of the last gem. While collecting gems, there are a number of enemies that try to stop Bentley and/or collect the gems for themselves. With two exceptions, if touched by the enemies he will lose one of his lives. Any gems collected by the enemies also result in a lower obtainable score for that screen. Likewise, if the last available gem is collected by the enemy, the player also loses the last gem bonus.